The Transportation Security Administration is warning parents: Know what your children are packing before you head to the airport, especially as vacation travel heats up this summer.

A TSA spokeswoman said officers found a small hatchet in a 16-year-old passenger's carry-on bag Wednesday at Orlando International Airport.

It was not the only concerning item TSA officials at a Florida airport found in a child's carry-on; earlier in the week, security officers said they found a grenade in a 12-year-old had in a carry-on at Jacksonville International Airport. The grenade was later determined to be inert and not dangerous, the TSA said.

Still, airport security officers issued a reminder of items that are not allowed to be carried onto a flight.

"Hatchets, knives, grenades and guns are not permitted in your carry-on bags," said TSA spokeswoman Sari Koshetz.

What can you bring on a flight?

The app will tell you if the item is permitted in a carry-on, a checked bag, or — in the case of grenades, including replica ones — neither.